Process of treating manganese-steel ingots.



. WENT OFFICE.

CHARLES G. OSBORNE, OF CHICAGQILLINOIS.

PROCESS TREATING MANGANESE STEEL INGO'IS.

mean a .I\T o Drawing.

Specification of Letters Patent. Application filed March 5,1913. Serial No. 752,240.

To all whom it. may concern: I

Be it known that LCHARLEs G. OSBORNE, a citizen of theUnited States, residin at Chicago, in the county of Cook and tate'v of Illinois, have invented certain new and useful Improvements in Processes'of Treating 'llfanganese-Steel Ingots, of which the following is a specification.

' drites forming to a greater extent as-the steel approaches the temperature of recrystallization, which may be roughly taken as 600 to 800 centigrade, but which is generally not above 750 centigrade, at which temperatures of recrystallization the ingot acquires a coarse crystalline structure. By heating an ingot to a temperature of approximately 1150+ 1215 I 0., the dendrites are gradually broken up, and an interlocking structure takes the place of the columnar dendritic structure. When this result. is accomplished, the ingot is readyfor roll-. ing. It will be apparent that the lower the temperature is to which the ingot cools slowly the longer will be the time required in order to break up the dendritic structure onreheating. I Thus the maximum time required when the ingot cools to or below its temperature'of recrystallization, whereas,

on the other hand, when the ingot is placed into a soaking. pit before its temperature has fallen below approximately 1150" 0., the time required is only that which is necessary to equalize the temperatureof the interior and exterior of the ingot, since-there has been only at the most aslight formation of dendrites.

It is the object of my-invention to treat manganese steel ingots so that if it is necessary to allow them to cool the reheating may be effected in a much less time than has heretofore been necessary. I accomplish 1 this result by quenching the ingot at as high a temperature as is possible, thereby rapidly cooling the steel to a temperature at which structural changes no longer take place and preventin an excessive formation of den-v drites, an as it were, holding the steel with the same structure which it had at the temperature at which it was quenched. It will now be evident that when an ingot is re heated forrolling it will be unnecessary to break up an excessive dendritic structure, 511106 by means of the quenching the formation of this structure has been prevented.

I In carrying out my invention, the ingot is preferably quenched as soon after it has beenstripped as is practicablei It will be apparent that by my invention a great economy in. time and fuel is obtained. Where an ingot is taken directly to the soaking pit after it has been stripped it is unnecessary to use my process, since the reheating begins before the temperature of the ingot has fallen sufficiently to allow the excessive formation of dendrites. If, onthe other hand, operating conditions necessitate delays and the cooling of the ingot, my process should be employed, -and the ingot quenched in water or other suitable fluid as soon "after stripping. as is possible. Similarly, in the case of overheated ingots, which are ordinarily impossible to roll or forge, I have found that by quenching such ingots their original structure seems to be restored,-

and they may then be reheatedand' rolled or forged'without difficulty.

It will be apparent to thoseskilled in the art that changes could be made in the exact invention which I have described without de arting from its, s irit or sco e.

, V'hat I claim is: p p

'1. The process of treating a cast body of manganese steel, which consists in quenching the unworked steel at 'a temperature above its point of recrystallization to rapidly reduce the temperature of said steel to. a point where no' further structuralchanges take place, and reheating to a roll- 7 ing temperature, substantially as described. 2.-The process-of treating'a manganese-- steel ingot, which consists in quenching the ingot at a temperature above its point of -recrystallization tov rapidly reduce the tem-' perature of said steel to a point where no further structural changes take place, and reheating said ingot to a rolling temperature, substantially as described.

3. The process of treating a manganese steel ingot, which consists in stripping the .Patented Apr. 21, 1914.

ingot, and quenching said ingot before its temperature has fallen below approximately 750 C. to rapidly reduce the temperature of said steel to a point where no further structural changes take place, substantially as described.

4. The process of treating a manganese steel ingot, which consists in stripping the ingot, quenching said ingot before its tem- 10 perature has fallen below approximately 750 C. to rapidly reduce the temperature of said steel to a point where no further structural changes take place, and reheating to a temperature of approximately 1175 C., substantially as described.

CHARLES G. OSBORNE.

Witnesses:

W. 0. POST,

D. V. IWEDALIE. 

